A roll-to-roll device could adopt a process of controlling a reel by the gravitational force to alleviate the non-uniform tension. In addition to detection of variation of tension, the roll-to-roll device still requires to monitor and regulate the detection of speed variation, during a process of transferring a film. Under a normal operation, when an automatic unwinding and tension monitoring module is activated, it cooperates with a winding module at the rear end for performing a transfer process. In the transfer process, regulating the non-uniform tension could be performed because of the difference of speed control between the front and the rear ends. When a steady state for the regulating is reached, the entire line for the transfer process can perform the transferring synchronously. For transferring an ultrathin glass substrate, sensors that are arranged in a load cell under a roller can be used to detect tension and speed so as to identify if a breaking or a cracking occurs in the substrate during the transfer process.
A conventional roll-to-roll device comprises a winding/unwinding mechanism, a buffering mechanism, a cushioning mechanism, an edge-following positioning mechanism, and a full-hood high-efficiency particulate air (HEPA) filter unit. The winding/unwinding mechanism uses a servomotor in cooperation with the load cell, to control the tension of the material roll. The buffering mechanism keeps manufacturing by a way of non-stop. The cushioning mechanism peels a film of a substrate and can be used, flexibly, in various production processes. The edge-following positioning mechanism involves an edge position control (E.P.C.) system to achieve neat and regular winding. The full-hood HEPA filter unit helps to maximize purity and cleanness.